Hatch's endorsement lends his credentials to a measure that is opposed by the anti-abortion movement. His announcement at a news conference was a coup for the cloning bill's previously announced sponsors, Sens. Edward Kennedy, D-Mass., Dianne Feinstein, D-Calif., and Arlen Specter, R-Pa.
In addition to Hatch's anti-abortion credentials, he brings a key Republican and conservative vote to a measure that thus far has been supported mostly by Democrats and liberal Republicans.
The bill, which is expected to be taken up later this month, bans cloning aimed at producing a child but permits scientists to create cloned embryos for use in research. Many scientists say that if tissues and organs can be created from the stem cells of cloned embryos, they could be especially useful in treating a wide variety of degenerative conditions, including Alzheimer's and Parkinson's disease and diabetes.
''Regenerative medicine is pro-life and pro-family,'' Hatch said, using a euphemism for cloning. ''If encouraged to flourish, it can improve the lives of millions of Americans and could lead to new scientific frontiers not now in sight.''
Senators who oppose the bill say that the practice will lead to genetic manipulation and greater inequality by paving the way for the creation of ''designer babies.'' Many find cloning objectionable because the cloned embryo is destroyed when cells are extracted for research.
Hatch said he had no such moral objections. He said ''human life . . . begins in a mother's nurturing womb,'' not when the clone is created in a laboratory. The bill Hatch has co-sponsored would provide a minimum 10-year prison sentence and $1 million fine for attempting to implant a clone in a woman's uterus or in an artificial womb.
Sen. Sam Brownback, R-Kan., co-sponsor of a bill that would ban all cloning, said the Hatch-sponsored measure would ''inevitably lead to the creation of human embryo farms where embryos will be grown to specification.''
The House of Representatives passed a version of Brownback's legislation last summer. President Bush supports the Brownback measure.
The Senate vote is expected to be close. Supporters of each bill say that each has about 40 supporters, with the balance held by undecided senators.